Rotopax and similar external gas storage units will for sure leak if they are overfilled and not vented when properly in hot conditions. People often keep them in places like tool boxes, which is one of the worst places to keep a gas tank due to the high temperatures. You should also not carry plastic gas containers in your bed without first putting a rubber bed matt down or something non-conductive, as static electricity can ignite the gas. Further, mounting your gas cans on the opposite side of your rig as the exhaust is a good idea. Just make sure to vent it when you stop for a frosty beverage or a bathroom break. As long as you buy a quality gas container and maintain it properly, you should be good to go. And if you're worried about your RZR consuming too much fuel when you're out on the trail, your concerns are not misplaced. A lot of Polaris RZRs run too lean, producing excessive engine and exhaust heat. A simple catalytic converter deletes and retune can fix that right up though.